John liddle



\ N UNITED sTATEs PATENT oEEIoE.

JOHN LIDDLE, OF NEW YORK, N. YQ

AIR-HEATING FURNACE.

Specification of Letters Patent No. 15,613, dated August 26, 1856.` j i To all whom 'it 'may concern.'

Be it known that I, JOHN LIDDLE, of the city, county, and State of New York, have invented certain new and useful Improvements in Constructing and Applying Furnaces for Heating Air, which I have herein described and ascertained as follows, refering to the accompanying drawings,` in

which- Figure l, is a vertical section; Fig. 2, is a perspective view of the lower portion of the radiator inverted; Fig. 3, a perspective view of the same part in another position; Fig. 4, a view of the top` of the radiator inverted; Fig. 5, the outside door; Fig. 6, main body of the furnace inverted; Fig. 7the same right side up; Fig. 8, the dome or top plate of the furnace; Fig. 9, plan of the main body of the furnace with all the attachments removed; Fig. 10, a side elevation of the same; Fig. 11, a section across a portion of the radiator; Fig. 12, a longitudinal section of the` same.

The same letters of reference refer to like parts in all the figures. i

My improvements are made on the parts A of an air heating `furnace above the fire pot,

j dicularly to the top; this-perpendicular part y consequently, the iire pot and parts below need no specific description. j

The main body of the furnace B is composed of a shell of cast iron made in one piece, which rises from the fire pot perpenis waved in its horizontal section, the curves being projected outward beyond the circumference of the fire pot; and having their lower ends gathered inward to a circle at the bottom the size of the fire pot with which it forms a joint. The curves are semicircles or about that figure; this part is all one single casting, and it consequently presents no vertical joints for the escape of gas, a defect which upright joints are apt to have from the diiculty of uniting, &c.; this specific configuration also facilitates the contraction of the cast-ing without injury, and retains it in its perfect formation. It is very important to have on the 'inside the openings for the escape of the products of combustion as low as possible, in order to avail myself of the reverberatory action of the fire in the most perfect manner; to effect this I attach to the inner surface of this casting, plates F, F, F, which extend from the top downward, as clearly shown in the drawing, so as to form short flues; and

it will be noted, that the joints between these plates F and the shell of the body B, need not be perfect, as noinjury can arise from any leakage of gas within the main body; on the outside also I have similar plates Gr, G, G, attached, which form air passages; thus the main body of my furnace is made up of a series of tubes, half of which open inward and half outward, without the possibility of any communication between the outer and inner surfaces, and without the use of cores in forming` the tubes, this feature is obviously important and constitutes one part of my invention, presenting a large surface for heat, and great capacity for imparting it by means of the flues or pipes on the outside, bringing the cold air into close contact with the heated surface, and those o-n the inside, which detain the heated products of combustion, and bring them into contact with the surface of the shell, while the construction is made simple,`without a single joint of communication between the outside and inside, or making any cores in casting.

The top of the main casting B is channeled and onto it the outer edge of the dome J is fitted with a luted joint, the edge being scalloped to suit the curvature of the shell, as clearlyshown in the drawing. The dome J is bell formed, and rises up to the height of the top of the ring E, to admit this dome, of sufficient size and height, without increasing the height of the furnace, or size of the ring E (both matters of great practicalimportance). The ring or hollow radiator E instead of being round, is made with straight inclined sides below its center, forming an acute angle, as seen by the drawing; this gives room for the enlarged dome with suii'icient air space between it and the ring E, which would not be the case were the lower part of the ring circular.

Directly over the internal flues formed by plates F, F, are circular openings through SFI portant for the following reason: I lead oft' the smoke pipe from the external circumference of the radiator and it is essential that I have power to turn it in any direction, to meet all the cases in practice for placing the furnace, which can be only effected by turning the radiator around as above stated; and further, it will not answer to lead the smoke pipe off directly over one of the ascending fiues D, as it would draw the whole current in that direction, and prevent the proper difusion of heat in the radiator; while on the other hand, there is not space enough between the ascending pipes for the purpose; therefore at the point where the smoke pipe connects, I cast the down pipe D closed at the bottom, so as to prevent the ascent of a current through it; this fully accomplishes all the desired points, it properly directs the currents, and enables me to keep the equi-distant openings all around and requires no other special contrivance for shifting the position of the ring.

On each side of the opening of the pipes D within the radiator E, are small ledges H, as seen in Fig. 3, that form a receptacle for ashes, soot, &c., and thus this part of the pipe at its lower angle becomes a nonconductorof heat. The purpose of this device is as follows: The air rising from the sides of the main body of the furnace, which is deflected by the lower surface of the ring, is absolutely warmer than the ring radiator itself, and it would consequently lose a part of its caloric, in heating up this ring if a nonconductor was not interposed, so that the ring would become an absorber of heat, instead of a radiator; the heat thus taken up would be carried off by the partially cooled products of combustion. The angular shape deflects the rising air with the least possible obstruction and presents a greater depth for the deposit of the nonconducting sootand ashes in its lower section.

The mouth or door of the furnace for the supply of fuel is marked C in the drawing this cast iron front diverging outward, and with an arched top forming a niche or alcove in the brick, for the purpose of enabling the attendant to get near to the fire. To prevent any radiation of heat through this cast iron front into the cellar I have provided an` outer door L, which covers the whole cast iron front, and is nearly flush with the brick work leaving a space of about five inches between the cast iron front and outer door L, and opposite to the mouth or door of the furnace C'there is an opening M in the iron door L, through which the air passes from the cellar for the support of combustion; this air passes down in the space above named to the opening below the grate, and during itspassage downward it is heated and thus rendered better fitted for the purpose of combustion, while it also carries off the heat radiated through the inner front and `doors and prevents its entering the cellar, by returning it to the fire in the manner described; while the air from the g cellar that would be so injurious to carry into the house, is entirely excluded therefrom, it being only used within the chamber of combustion.

Having thus fully described my improvement what I claim therein as new, and for which I desire to secure Let-ters Patent isl. The construction of the main body of the furnace substantially as herein de scribed, forming by plates F, F, attached to the internal surface, a series of tubes around its circumference so as to form the smoke flues, without any vertical joints between the interior and exterior and without the employment of cores in casting as set forth.

2. I also claim making the lower sections of the radiator E, with the sides forming an acute angle, and in combination with the ledges H, H, in the manner and for the purposes set forth.

JOHN LIDDLE Witnesses :k

JOHN M. EAGER, DANIEL P. MARSHALL. 

